Obviously that "No OS" part is a gotcha, but School Districts are practically given Microsoft licenses for pennies on the dollar, so pushing an image of Windows 10 Enterprise isn't exactly a big ask.
The biggest downside of Windows isn't the cost of the devices, it is the staffing costs. With Chromebooks you may be able to spread one full time IT support tech between three or four schools, with Windows it might be one support tech for two schools, and they'll need to be shadowed by people handling systems like AD/Exchange/et al.
I will say that in my limited experience larger school districts do very well with a Windows solution, but smaller ones do better with Chromebooks. That's because larger ones can absorb the cost of the AD/Exchange/server admin easily, whereas for smaller ones you'll have to lose IT support tech staff to go handle that (which hurts end users).
Microsoft has been trying to combat some of these limitations with Azure/Office 365. They, again, give School Districts a huge discount and it allows the school district to outsource some of their staffing needs to Microsoft. Will it work? Time will tell.
I will add this: iPads have been an unmitigated disaster. Everyone rushed to buy them and then had no idea what to do with them once they got them. No money was spent on apps or lesson plans (that focused around an iPad), and even for generic "research" carts they're very underwhelming.
Both Chromebooks and Windows (w/Office) do what students and teachers need: Student email, student portal, research, typing, and spreadsheets.
Ever watch a student try to research something and type a report on that subject using an iPad? It is damn painful, many just start writing the information on paper, then writing up their report at the end, whereas a Chromebook and Windows machine (and MacOS in fairness) are full on multitasking.
Watch this video of someone multitasking on a Chromebook[0] and now an iPad[1]. The iPad is a toy by comparison. I won't even insult anyone's intelligence by linking to videos of Windows/MacOS, both are solid as a rock for multitasking too (MacOS just isn't "realistic" for budgetary reasons).
[0] https://www.youtube.com/watch?v=5-AJasVMb1Y [1] https://www.youtube.com/watch?v=jorwzOsPAYs